Qingquan Li

# 1. Two's complement **Unsigned numbers** involve only non-negative numbers, like 0 and 3. **Signed numbers** involve both positive and negative numbers, like 3 and -3. In binary, a **signed-magnitude...

References: - https://www.digitalocean.com/community/tutorials/how-to-set-up-django-with-postgres-nginx-and-gunicorn-on-ubuntu-20-04#creating-the-postgresql-database-and-user # 0. Before config In this blog, I logged into an Ubuntu server with the username "Jake" and created a database as well as a database role...

References: - https://docs.github.com/en/get-started/quickstart/contributing-to-projects - https://www.freecodecamp.org/news/how-to-use-git-and-github-in-a-team-like-a-pro/ - https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue # Git Workflow  (source: http://www.davidgw.com/git-workflow-model/) # Steps 1. Fork the owner's repo (upstream) The original(owner) repo should include 2 branches: main(master), dev...

Reference: Book: *Starting Out with C++ from Control Structures to Objects, by Tony Gaddis, ninth edition* > Concept: File stream objects have member functions for more specialized file reading and...

# Vim Configuration References: - https://vimconfig.com/ - https://www.shortcutfoo.com/blog/top-50-vim-configuration-options/ - https://www.freecodecamp.org/news/vimrc-configuration-guide-customize-your-vim-editor/ My Vim configuration: https://gist.github.com/Qingquan-Li/b4eae570d054fd48495d73efa04d6a86 # Vim commands References: - https://yannesposito.com/Scratch/en/blog/Learn-Vim-Progressively/ - https://www.shortcutfoo.com/app/dojos/vim/cheatsheet -  ### Copy all text to system...

简单的来说， vi是老式的文书处理器，不过功能已经很齐全了，但是还是有可以进步的地方。vim则可以说是程式开发者的一项很好用的工具，可以将vim视作vi的进阶版本，vim可以用颜色或底线等方式来显示一些特殊的资讯，支援正规表示法的搜寻架构、多档案编辑、区块复制等等。 # Vi 的使用 > 基本上vi共分为三种模式，分别是『一般指令模式』、『编辑模式』与『指令列命令模式』。这三种模式的作用分别是： - 一般指令模式(command mode) 以vi （或vim）打开一个档案就直接进入一般指令模式了(这是预设的模式，也简称为一般模式)。在这个模式中， 你可以使用『上下左右』按键来移动游标，你可以使用『删除字元』或『删除整列』来处理档案内容， 也可以使用『复制、贴上』来处理你的文件资料。 - 编辑模式(insert mode) 在一般指令模式中可以进行删除、复制、贴上等等的动作，但是却无法编辑文件内容的！要等到你按下『i, I, o, O, a, A, r, R』等任何一个字母之后才会进入编辑模式。注意了！通常在Linux中，按下这些按键时，在画面的左下方会出现『INSERT或REPLACE』的字样，此时才可以进行编辑。而如果要回到一般指令模式时，则必须要按下『Esc』这个按键即可退出编辑模式。 - 指令列命令模式(command-line mode) 在一般模式当中，输入『 :...

Reference: Book: *Starting Out with C++ from Control Structures to Objects, by Tony Gaddis, eighth edition* > Concept: All stream objects have error state bits that indicate the condition of...

Reference: Book: *Starting Out with C++ from Control Structures to Objects, by Tony Gaddis, eighth edition* > Concept: File stream objects may be passed by reference to functions. The internal...

# 1. File Stream Data Types: | Data Type | Description | | --------- | ------------------------------------------------------------ | | ifstream | Input File Stream. This data type can be used only...

Reference: Book: *Starting Out with C++ from Control Structures to Objects, byTony Gaddis, eighth edition* > Concept: Aggregation occurs when a class contains an instance of another class. ## Example:...